Chapter4受精生物学 (Fertilization) 1. 花粉在柱头上萌发和花粉管伸长 Pollen germination and pollen tube growth 2. 花粉管到达胚珠和进入胚囊 Entry of pollen tube into stigma and style,and to embryo sac Biology of plant reproduction Biology of plant reproduction 1 Chapter 4 受精生物学 （Fertilization） 1. 花粉在柱头上萌发和花粉管伸长 Pollen germination and pollen tube growth 2. 花粉管到达胚珠和进入胚囊 Entry of pollen tube into stigma and style, and to embryo sac